Fry the onion, garlic and ginger in the coconut oil for 3 minutes in a large frying pan.
Add the curry powder, turmeric and garam masala to the pan, stir together and fry for 2 minutes. Add another tsp of oil or a tbsp of water if the mixture is sticking.
Add the stock, lemon juice, soy sauce and sugar to the pan.
In a small bowl, mix together the cornflour and water. Add to the pan and stir together. Simmer for 3 minutes to allow the sauce to thicken.
Let the curry sauce cool and when it is safe to do so, add the curry sauce to a blender and blend until smooth (don’t skip this step!). Alternatively, you can use a stick blender.
